Transfer mechanism for nut-making machines



G. 5. SMITH March 24, 1931 TRANSFER MECHANISM FOR NUT MAKING MACHINES Original Filed June 4, 1926 3 Sheets-Sheet l IN VEN TOR.

BY W 1 Map ATTORNEYS.

March 24, 1931. G, 5 BMW-H 1,797,449

TRANSFER MECHANISM FOR NUT MAKING MACHINES I5 Sheets-Sheet z Original Filed June 4, 1926 IN V EN TOR.

7k, ATTORNEYS.

March 24, 1931. e. s. SMITH 197979449 TRANSFER MECHANTSM FOR NUT MAKING MACHINES Original Filed June 4. 1926 3 Sheets-Sheet 3 IN V EN TQR.

v BY w 7 afl% 3 A TTORNEYS.

Patented Mar. 24, 1931 UNITED STATES PATENT- GEORGE S. SMITH, OF PITTSBURGH, PENNSYLVANIA, ASSTGNOR T0 PITTSBURGH SCREW & BOLT CORPORATION, A CORPORATION OF PENNSYLVANIA TRANSFER MECHANISM FOR NUT-MAKING- MACHINES Original application filed June 4-, 1926, Serial No. 113,663. Divided and this application filed January 13, 1928. Serial No. 246,590.

This invention relates to nut making ma chines and more particularly to mechanism for transferring nut blanks from one position to another in such machines, and this application is a division of my earlier application Serial No. 113,668, filed June 4, 1926.

An object of this invention is to provide a transfer mechanism of the type described of improved construction and more efficient operation than similar mechanisms now in use and known to me.

A further object is to provide a transfer mechanism for nut machines which will be rugged in construction, reliable in operation and simple to manufacture and assemble.

These and other objects which will be apparent to those skilled in this particular art are attained by means of the invention illustrated in the accompanying drawings in which Figure 1 is a plan view of nut blanl: transfer fingers constructed in accordance with one embodiment of this invention. Fig. 2 is a similar view showing the fingers in open position. Fig. 3 is a transverse sectional view on the line 33 of Fig. 1. Fig. 4 is a partial sectional view showing the transfer mechanism slide in elevation. Fig. 5 is a transverse sectional view on the line 5--5 of Fig. 1. Figs. 6, 7 and 8 are detail views of the transfer finger operating slides. Fig. 9 is a transverse sectional view through a portion of a machine illustrating the operating means for the transfer mechanism, and Fig. 10 is a section on line 1010 of Fig. 9.

The particular embodiment of the present invention which has been chosen for the purpose of illustration is shown in connection with a nut machine 10 having the usual crowning die 11 and finishing die 12, and the mechanism embodying the present invention is provided for the purpose of transferring nut blanks from the crowning die to the finishing die and properly positioning such blanks in the latter die. When employed in connection with a machine such as that disclosed in my above noted application, the nut blanks are fed from a blanking die, not shown, through atransfer chute 13 to the delivery station 14, illustrated in. dotted lines in F ig. 1.

The transfer chute conveys the rough blanks to a position where they will be engaged by transfer fingers 98 for conveyance to the finishing dies. These transfer fingers are so arranged that their movements are entirely rectilinear. They move bodily toward each other to grip a. nut blank, then bodily in a longitudinal direction to carry the nut to the desired point, then bodily away from each other to release the nut blank and they are finally returned to their original position by bodily longitudinal movement. By providing transfer fingers which are moved in such a manner it is possible for a single set of fingers to simultaneously grip and release a plurality of nutblanks' The transfer fingers are supported in slots 99 extending longitudinally of finger supporting cross slides 100 and pivoted on pins 99. 101 extending across the bottom surfaces for receiving an associated dove tail 102 formed on the upper surface of a finger operating slide 103 slidably mounted on the machine bed. 1

A slight amount of play exists between each transfer finger and the associated slot 99 in the supporting cross slide 100, and the extending ends of the transfer finger are pressed toward each other by light helical springs 10 which are secured between projecting pins extending out from the associated ends of the transfer arms and similar pins on the adj acent sections of the arm supporting cross slides. This provides a floating effect which enables the fingers to yield in one lateral direction or the other in case a nut is shifted laterally by a descending punch as is the case when the hole in a nut is slightly oif center. Set screws 104 limit the extent of lateral movement to which the fingers can be sub jected. Y

The dove tails 102 are hollowed out so as to form aligned channels 105 for receiving a spring 106 secured to pins 107 in the dove tail receiving channel of each cross slide 100 for the purpose of drawing the cross slides with their supported transfer fingers toward each other.

Each arm supporting cross slide is pro- Each fingersupporting slide has a slot I vided with an inwardly extending cam surface 108 adapted to cooperate with associated cam surfaces 109 formed on opposite sides of a central finger spreader cam block 110 mounted for sliding movement between the recessed dove tails 102 of the finger operating slide 103 and slidably secured to the finger operating slide by a bolt 111 extending downwardly through an elongated slot 112. It is apparent that the movement of the cam block or spreader block 110 relatively to the cross slides 100 will cause the transfer fingers to be moved apart when the spreader block is moved in one direction and to approach each other under the influence of the spring 106 when the block is moved in the other direction. Such movement of the finger opening and closing cam block 110 is obtained by means of a block operating yoke 113 having a pin 114 extending downwardly from the yoke between the upwardly extending ends 115 of the spreader block. The operating yoke is secured to cross bars llfi'pivoted for oscillatory movement upon a bearing 117 supporting a cam shaft 118 having a yoke oscillating cam 119 secured to the end thereof between the two arms of the yoke. Gears 1-20 connect the yoke operating cam shaft with a driving shaft (not shown) driven from a cam shaft 123 extending across the bottom of the machine and driven from any suitable source of power. The cam shaft 123 extending across the bottom of the machine has a cam 124, see Fig. 9, secured thereto operatively associated with a reciprocatory arm 125 having a roller 126 for cooperation with the cam and slidably mounted in the supporting bracket 127 extending downwardly from the bottom of the machine bed. The arm 125 is adapted to oscillate the transfer finger operating lever 128 mounted at its lower end upon a supporting pivot 129. A spring 130 is provided for drawing the lever inwardly and for holding the operating arm 125 in operative engagement with the driving cam. It will be apparent that the transfer fingers are moved in the nut transferring direction by the spring 130 so that any amming of the nuts or the like will not cause the breakage of any parts. In order to provide an additional safety device the transfer finger operating lever 128 is so constructed and arranged as to yield in case of undue resistance to the return movement of the transfer fingers. As illustrated, this is accomplished by providing the upper end of the operating lever128 with a recess or slot 131 extending inwardly from one end thereof; An arm 132 is mounted upon a pivot pin 133 extending across the lower end of the slot and the upper end of the extending arm is bolted between the downwardly depending ears 134 formed on the bottom of the transfer finger operating slide 103. Adjacent the upper end of the arm receiving slot 131 the lever 128 is provided with a spring pressed detent 135 which normally seats in a depression 136 formed in a co-operating plate 137 mounted in the arm. It will be apparent that undue resistance to the return of the transfer fingers will cause the detent to yield permitting pivoting movement between the lever 128 and the arm 132. In view of the fact that both the transfer finger slide operating lever 128 and the spreader block 110 are driven from the same cam shaft 123, the timing and coordinating of the operations of the respective cams is very simply and accurately accomplished.

Assuming that the transfer fingers are in the position shown in Fig. 2, where the nut blank engaging notches 138 which are formed intermediate the ends of the fingers are positioned opposite the blank just delivered from the transfer chute while the blank engaging notches 139 are positioned opposite the champfering or crowning die, it will be apparent that movement of the spreader block 110 to the right under the impulse of the cam driven oscillating yoke 113 moves the cam surfaces 109 of the spreader block away from between the cams 108 of the finger supporting cross slides so as to permit the latter to be drawn toward each other by the connecting spring 106. This moves the fingers from the open position bodily toward each other to the closed position where the intermediate notches 138 engage a nut blank delivered from the transfer chute while the notches 139 in the ends of the fingers engage a nut which has previously been delivered to the champfering die. The cam 124 then permits the lever operating spring 130 to draw the transfer finger operating lever 128 toward the right and this shifts the finger reciprocating slide 103 inwardly until the nut blank engaged by the intermediate notches 138 has been shifted from a position beneath the transfer chute to the champfering or crowning die 140 and the blank engaging notches 139 have shifted a crowned blank from the champfering die to a finishing die 141. The distance between the upwardly extending ends 115 of the spreader block 110 is such that the block can move longitudinally withthe transfer finger and shifting slide before the operating pin 114 of the oscillating yoke 113 engages the opposite end 115. The yoke is then shifted in the opposite direction and the spreader block moved to the left in Fig.

- 1 to the relative position shown in Fig. 2.

This causes a bodily movement of the transfer fingers away from each other after which the earn 124 oscillates the slide shifting lever 128 and retracts the opened fingers to the position shown in Fig. 2. It will be apparent that such a mechanism provides transfer fingers which are movable in rectilinear paths only. They release and engage a plurality of nut blanks simultaneously and are capable of engaging a blank which may be positioned at one side of their medial line.

in operation the transfer chute delivers a blank to the transfer fingers 98 which are then moved bodily toward each other to permit such blank to be engaged by the cooperating notches 138 of the transfer fingers. The latter are then shifted so as to carry the blank over the champfering die. The bodily movement of the fingers toward each other has caused the notches 139 to engage a previously champfered blank and the lateral movement has conveyed the champfered blank to a posit-ion over the finishing die 141 while the unchampfered blank is carried by the notches 138 to the champfering die 140.

v The transfer fingers are yieldingly shifted in one direction by the spring 130 while any jamming to resist the movement in the opposit-e direction will cause a yielding of the detent 135 to permit the finger slide operating arm 132 to break from the operating lever 128 and prevent any possible breakage of parts.

Although I have described a transfer mechanism embodying specific details of construction, it will be apparent that various changes, additions, substitutions and omissions can be made therein without departing from the spirit of this invention or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. The combination in a nut making ma chine of a pair of transfer fingers adapted to shift nut blanks from one position to another, a finger operating slide for reciprocating said fingers, finger supporting cross slides mounted on said operating slide and provided with inwardly extending cam surfaces, a spreader block slidably mounted on said operating slide between said cross slides and cooperating with said cam surfaces, an oscillatory yoke for operating said spreader block so as to move said fingers bodily away from each other when in one position and for shifting said spreader block to permit said fingers to be moved bodily toward each other when in the other position.

2. The combination in a nut making machine of a transfer mechanism adapted to shift nut blanks from one position to another, means for reciprocating said mechanism in cluding an oscillatory lever, a spring for moving said lever in one direction, a cam for moving said lever in the opposite direction, an arm pivoted to said lever and secured to said mechanism and a spring pressed detent for normally holding said arm rigid with said lever.

8. In a nut making machine, in combination, a movable support, finger supporting members dovetailed on the support and movable laterally thereon as the support moves longitudinally, a transfer finger on each of GEORGE S. SMITH. 

